By building DML code into PostgreSQL, we can avoid duplicate implementation of data-related code in multiple separate applications that interface with the database. This ensures consistent execution of DML for data validation, data cleansing, or other functionality such as data auditing (i.e., logging changes) or maintaining a summary table independently of any calling application. In this blog, we’ll look at the basics of triggers and stored functions in PostgreSQL.

With this blog post we aim to give you an introduction to failover handling in MySQL & MariaDB by discussing what failover is, why it is unavoidable and what the difference is between failover and switchover. We also discuss the failover process in its most generic form and touch a bit on different issues that you will have to deal with in relation to the failover process.

Watch the replay of this webinar with Vinay Joosery, CEO at Severalnines, during which he explains key disaster recovery concepts and walks us through the relevant options from the MySQL & MariaDB ecosystem in order to meet different tiers of disaster recovery requirements; and learn how ClusterControl can help user fully automate an appropriate disaster recovery plan.

Asynchronous replication places no low latency demands on the network, so it is possible to keep Galera Clusters in sync even when they are thousands of miles apart and utilise low-cost connections. We effectively can achieve a global system of loosely-coupled clusters. However, managing the global state translates into managing failover and failback operations at both node and cluster level.

Failover is a procedure that we hope we won’t have to use, but we must know how it works. In this blog, we will be cover the basic definitions of failover in PostgreSQL replication, and some example scenarios where failover can be useful.

Database failures can happen at different levels, from schema corruption on an individual server to hardware or even an entire datacenter going down. So how do we troubleshoot and fix these? In this blogpost, we will walk through 6 different failure scenarios and see how we recovery from them.

Databases are a part of a wider mesh of infrastructure components, and as such, failover usually has some impact on more than just the database. Therefore, the failover software needs a mechanism to orchestrate changes across the infrastructure. This blog post describes how ClusterControl can be integrated with external infrastructure and tools, through the use of scripts executed during failover process.

This is the follow up to the popular blog ‘My favourite PostgreSQL queries and why they matter’. This new blog focusses on a particular query, multi-row UPDATE with a single CASE expression, and makes comparisons between that particular query, and one involving multiple single UPDATE statements.